A 2-year trial of prospective HLA-DR matching: effects on renal allograft survival and rate of transplantation.

In a 2-year trial at a single center, prospective HLA-DR matching for cadaver renal transplantation exerted a stronger effect than either HLA-A and B matching or blood transfusion. One-year cumulative graft survivals for two-DR-matched organs was 92%. Grafts matched for one DR antigen had a cumulative 1-year graft survival of 65% whereas grafts matched for zero DR antigens had a cumulative 1-year survival of 41%. When all cadavers with less than two identifiable DR antigens were excluded from this analysis, however, the graft survivals of the groups known to be mismatched for one or two DR antigens were similar (61% versus 59%). Grafts matched for three or four HLA-A and B antigens did somewhat better than those matched for only zero, one, or two HLA A and B antigens (74% versus 59%, 1-year survival). This effect was only demonstrable in the zero- and one-DR-matched group. Similarly, prior blood transfusion exerted a modest effect (transfused versus nontransfused, 71% versus 56% 1-year graft survival) that was also most evident in the zero- and one-DR-matched groups. The institution of this trial was also associated with a 35% annual increase in the rate of transplantation and a 50% reduction in median patient waiting time. DR typing of cadaveric donors is feasible and highly desirable. Multicenter pooling of DR-typed donors is thus predicted to lead to optimal matching for a high proportion of renal transplant candidates.